The Stovebolt Site Forums The Shop Area Driveline Speedo Cable Connection

1950 Chevy 3100

Had mechanic rebuild all gauges.

All operate except speedo. Odometer is working but speedo only registers 10 mph when driving@ 40-50 mph.

Mechanic tells me that speedo drive gear is broken and to fix he must pull and disassemble transmission.

Why would odometer operate if speedo drive gear was broken?

Thanks for help on this.

sounds like the speedo needs a good cleaning, or something is binding, possibly even the needle touching the glass .... the odo runs off a spiral gear driven by the cable, the speedo is turned by a bell with a magnet inside, which is driven by the cable .... here's the guts - if the odo is working and the speedo is moving at all, there's no "broken gear" in the trans, and even if the trans gear was bad, it is accessed directly, without even removing the trans, let alone disassembling it - cross that mechanic off your call list

Bill

Thanks Bill,

Really appreciate your input. It's frustrating to put your trust in someone who supposedly specializes in restoring these vehicles and can't give you a straight answer.
Just a side note.
Speedo and odometer stopped working today. Got under truck, speedo cable was hanging free. Looks like the cable was never mounted to housing correctly and worked its way loose.

Thanks again,
Kurt

could be the cable end wasn't fully engaged in the gear socket, if you get it back on right it might even be working again! look at the end of the inner cable and make sure it still looks square and hasn't been chewed up

Bill